Solid-state imaging device and solid-state imaging device array

ABSTRACT

In a photosensitive part  10 , arranged from pixels A aligned in n rows and m columns, supply wiring lines  13   a  and  13   b , which are electrically connected and apply transfer voltages to transfer electrodes  12   a  to  12   d , formed of polycrystalline silicon, are installed so as to cover parts of the top surfaces of light-shielded pixels D. Dead zones for installing supply wiring lines, which existed priorly at the respective end parts in a horizontal direction of a photosensitive part, can thereby be eliminated and the photosensitive part can be made wide. Also, in the case where a plurality of the solid-state image pickup devices are used upon being made adjacent each other in the horizontal direction, parts at which image pickup is not carried out can be lessened. Also, the amount of lowering of the amounts of incident light on light-shielded pixels D can be corrected based on the output signals from light-shielded pixels D or other pixels A. By the above, a solid-state image pickup device, with which the dead zones can be made small and the photosensitive part can be made wide, and a solid-state image pickup device array, using such solid-state image pickup devices, can be realized.

TECHNICAL FIELD

This invention concerns a solid-state image pickup device and asolid-state image pickup device array.

BACKGROUND ART

FIG. 7A shows a top view of a prior-art full-frame transfer solid-stateimage pickup device (FFT CCD) or frame transfer (FT) CCD for the case oftwo-phase drive, and FIG. 7B shows a sectional view of the same alongarrows IV-IV.

A CCD 100 comprises a semiconductor substrate 101, transfer electrodes102, set on a top surface side of semiconductor substrate 101, andsupply wiring lines 103, electrically connected to transfer electrodes102. A photosensitive part, which picks up an image of light that ismade incident on CCD 100, is arranged. The photosensitive part has aplurality of pixels E aligned in a horizontal direction and a verticaldirection. By light being made incident on pixels E, charges aregenerated in the interiors of pixels E and image pickup of the image oflight is carried out thereby.

For each single pixel E, a predetermined number of transfer electrodes102 are set on top of pixel E with their longitudinal direction beingset along the horizontal direction of the photosensitive part and, bybeing supplied vertical transfer voltages, transfer charges in thevertical direction. Supply wiring lines 103 are the wiring for supplyingthe transfer voltages to the transfer electrodes 102 and are disposed,with their longitudinal direction being set along the verticaldirection, at the respective end parts of CCD 100, which are dead zonesF where an image of light is not picked up.

When an image of light is made incident from the top surface side of CCD100, charges are generated in the interiors of pixels E. Then by thevertical transfer voltages being supplied to transfer electrodes 102 viasupply wiring lines 103, the charges are transferred inside pixels E inthe direction of arrow c.

With an FFT CCD or an FT CCD, a polycrystalline silicon (polysilicon) orother light transmitting material is used as the material of transferelectrodes 102. Supply wiring lines 103, which are formed of aluminum orother metal and are disposed at the respective ends of transferelectrodes 102, are used for supplying voltages to transfer electrodes102.

DISCLOSURE OF THE INVENTION

Since supply wiring lines 103, which are formed of aluminum, etc., blocklight, in the prior-art CCD, supply wiring lines 103 are installed atdead zones F at the respective end parts of CCD 100 as described above.However, the existence of dead zones F is a problem in terms of makingeffective use of the surface of CCD 100, and thus dead zones F arepreferably as small as possible. Such dead zones F also present problemsin cases where a plurality of solid-state image pickup devices arealigned so as to be adjacent each other in the horizontal direction.That is, by dead zones F existing between the plurality of alignedsolid-state image pickup elements, parts of an image of light will notbe picked up.

This invention has been made to resolve the above issues and an objectthereof is to provide a solid-state image pickup device, with which deadzones can be made small and a photosensitive part can be made wide, anda solid-state image pickup device array that uses such solid-state imagepickup devices.

In order to achieve the above object, this invention provides asolid-state image pickup device comprising: a photosensitive part,having m×n pixels, formed on a semiconductor substrate, which includes ap-type semiconductor layer and an n-type semiconductor layer, andaligned two-dimensionally along m columns (where m is an integer of 2 ormore), which partition a horizontal direction, and n rows (where n is aninteger of 2 or more), which partition a vertical direction, and pickingup an image of light that is made incident thereon; a transferelectrode, being installed on top of the pixels with the longitudinaldirection thereof being set along the horizontal direction of thephotosensitive part and being applied a vertical transfer voltage thattransfers charges generated in the pixels in the vertical direction; anda supply wiring line, formed of metal or metal silicide, installed so asto cover a part of a light-shielded pixel, which is a predeterminedpixel among the pixels, and with the longitudinal direction thereofbeing set along the vertical direction of the photosensitive part, beingelectrically connected to the transfer electrode, and applying thevertical transfer voltage to the transfer electrode; wherein beingarranged to enable correction of the amount of lowering of an outputsignal, output by the light-shielded pixel, due to the supply wiringline.

With this invention's solid-state image pickup device, since dead zonesfor installing supply wiring lines at the respective end parts in thehorizontal direction of the photosensitive part can be eliminated by theinstalling of the supply wiring line, formed of metal or metal silicidethat blocks light, on top of pixels, the photosensitive part can be madewide. Also by eliminating the dead zones, parts at which image pickupcannot be performed can be lessened in cases where a plurality of thesolid-state image pickup devices are used upon being made adjacent eachother in the horizontal direction. Also, the supply wiring line isarranged to cover only a part of the light-shielded pixel. Since lightis made incident on the other part of the light-shielded pixel, anoutput signal, which is lowered to some degree in output amount, isoutput from the light-shielded pixel. Thus with the solid-state imagepickup device of the above arrangement, the lowering of the incidentlight amount on the light-shielded pixel can be corrected based on theoutput signal.

Also, this invention's solid-state image pickup device array ischaracterized in that a plurality of the above-described solid-stateimage pickup devices are aligned in a mutually adjacent manner with thephotosensitive parts aligned in the horizontal direction. Since theabove-described solid-state image pickup device does not require deadzones for installing supply wiring lines, by aligning a plurality of thesolid-state image pick-up devices, the intervals between the respectivephotosensitive parts can be made narrow. Non-image-pickup parts thatexist in an image that has been picked up by the solid-state imagepickup device array can thus be made small.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic arrangement diagram of a first embodiment of thisinvention's solid-state image pickup device as viewed from the topsurface side.

FIG. 2A and FIG. 2B are (A) a top view and (B) a section along arrowsI-I showing a part of the arrangement of a CCD of the solid-state imagepickup device shown in FIG. 1.

FIG. 3A and FIG. 3B are tables showing (A) an example of output signaldata from pixels A and (B) an example of output signal data fromlight-shielded pixels D and pixels A in an FFT CCD with 1024 columns and64 rows.

FIG. 4 is a schematic arrangement diagram of a solid-state image pickupdevice array using this invention's solid-state image pickup devices asviewed from the top surface side.

FIG. 5A and FIG. 5B are (A) a top view and (B) a section along arrowsII-II showing a part of the arrangement of a CCD of a solid-state imagepickup device of a second embodiment.

FIG. 6A and FIG. 6B are (A) a top view and (B) a section along arrowsIII-III showing a part of the arrangement of a CCD of a solid-stateimage pickup device of a third embodiment.

FIG. 7A and FIG. 7B are (A) a top view of a prior-art full-frametransfer solid-state image pickup device (FFT CCD) or frame transfer(FT) CCD for the case of two-phase drive and (B) a sectional view alongthe arrows IV-IV of the same.

BEST MODE FOR CARRYING OUT THE INVENTION

Preferred embodiments of this invention's solid-state image pickupdevice and solid-state image pickup device array shall now be describedalong with the drawings. In the description of the drawings, the sameelements shall be provided with the same symbols and redundantdescription shall be omitted. Also, the dimensional proportions in thedrawings may not necessarily match those of the description.

FIG. 1 is a schematic arrangement diagram of a first embodiment of thisinvention's solid-state image pickup device as viewed from the topsurface side. In this embodiment, the solid-state image pickup device isequipped with a two-phase drive FFT CCD. This FFT CCD has an arrangementwherein charges, which are generated by the incidence of an image oflight from the top surface side of a photosensitive part, aretransferred in the photosensitive part.

This solid-state image pickup device is arranged from a CCD 1, which isan FFT CCD, and a charge transfer control part 20. Of these, CCD 1 isequipped with a photosensitive part 10, a horizontal shift register 15,and an amplifying part 16.

Photosensitive part 10 is divided in its horizontal direction into mcolumns H1 to Hm (where m is an integer of 2 or more), each having itslongitudinal direction aligned along the vertical direction, and isdivided in its vertical direction into n rows V1 to Vn (where n is aninteger of 2 or more), each having its longitudinal direction alignedalong the horizontal direction, and is thereby arranged from m×n pixelsA. When an image of light is made incident from the top surface side ofphotosensitive part 10, charges are generated inside pixels A.

Transfer electrodes (not shown), which are formed of polycrystallinesilicon, etc. that has a light transmitting property, cover the entiretyof photosensitive part 10 at the top surface side of photosensitive part10 and are positioned in the direction (horizontal direction) parallelto the longitudinal direction of the respective rows Vj (j=1 to n). Inaccordance to two-phase drive, two or four transfer electrodes areinstalled for each row. Supply wiring lines 13 a and 13 b, for supplyingvertical transfer voltages P1 and P2, which are in accordance withtwo-phase drive, to the transfer electrodes, are installed with theirlongitudinal direction being set in the direction (vertical direction)parallel to the longitudinal directions of the respective columns Hi(i=1 to m) of photosensitive part 10.

These supply wiring lines 13 a and 13 b are formed of aluminum or othermetal or metal silicide of low electrical resistance and are installedon top of the pixels of columns H1 and Hm, which among the m columns arelocated at the respective ends of photosensitive part 10, so as to covera part of each pixel. Here, since a part of each light-shielded pixel Dthat is covered by supply wiring lines 13 a or 13 b is not covered andlight is made incident thereon, charges due to this part is generated ineach light-shielded pixel D. Also supply wiring lines 13 a and 13 b areinstalled in a manner such that one set of wiring lines, comprising thetwo wiring lines of one each of supply wiring lines 13 a and 13 b, isinstalled per column.

Supply wiring line 13 a is electrically connected to correspondingtransfer electrode among the two to four transfer electrodes that areinstalled for each row Vj and supplies transfer voltage P1 to thetransfer electrode. Supply wiring line 13 b is likewise electricallyconnected to corresponding transfer electrode and supplies transfervoltage P2 to the transfer electrode. By these vertical transfervoltages P1 and P2 being supplied to the transfer electrodes, a verticalshift register, which accumulates the charges generated in the interiorof pixels A and transfers these charges in the vertical direction(direction of arrow a in the Figure), is arranged. By vertical transfervoltages P1 and P2 being controlled by charge transfer control part 20,the charges inside pixels A are transferred.

Horizontal shift register 15 receives the charges, which were generatedin the respective pixels A and were transferred in the verticaldirection of photosensitive part 10, from photosensitive part 10,transfers these charges in the horizontal direction (arrow b), andoutputs the charges to amplifying part 16. The charges output fromhorizontal shift register 15 are amplified by amplifying part 16 and arethen output to the exterior of the solid-state image pickup device asoutput signals according to the respective pixels.

FIG. 2A and FIG. 2B are (A) a top view and (B) a section along arrowsI-I showing a part of the arrangement of CCD 1 of the solid-state imagepickup device shown in FIG. 1. CCD 1, shown in FIG. 2A and FIG. 2B,comprises a semiconductor substrate 11, transfer electrodes 12 a to 12d, supply wiring lines 13 a and 13 b, and an insulating layer 14.

Semiconductor substrate 11 comprises a p⁺ type semiconductor substrate111, which is of a p⁺ conduction type and serves as the base ofsemiconductor substrate 11, a p-type semiconductor layer 112, which isan epitaxial layer that is formed on the top surface side of p⁺ typesemiconductor substrate 111, and an n-type semiconductor layer 113 and ap⁺ type semiconductor layer 114, which are formed further on the topsurface side. N-type semiconductor layer 113 and p⁺ type semiconductorlayer 114 are disposed in alternating manner in the horizontaldirections with the vertical direction of photosensitive part 10 beingtheir longitudinal direction. N-type semiconductor layer 113 and p-typesemiconductor layer 112 form a pn junction, and n-type semiconductorlayer 113 serves as a photosensitive region that generates charges uponincidence of an image of light. N-type semiconductor layer 113 forms therespective columns Hi (i=1 to m) of photosensitive part 10. P⁺-typesemiconductor layer 114 form isolation regions C that separate therespective columns Hi.

Also, transfer electrodes 12 a to 12 d are installed via insulatinglayer 14 on the top surface of semiconductor substrate 11. Transferelectrodes 12 a to 12 d are installed in an alternating manner in thevertical direction with their longitudinal direction set along thedirection parallel to the horizontal direction of photosensitive part 10and form the respective rows Vj (j=1 to n) Pixels A, which are alignedin n rows and m columns, are thus formed by n-type semiconductor layer113 and transfer electrodes 12 a to 12 d.

Supply wiring line 13 a is electrically connected to transfer electrodes12 a and 12 b and vertical transfer voltage P1 is supplied to transferelectrodes 12 a and 12 b. Likewise, supply wiring line 13 b iselectrically connected to transfer electrodes 12 c and 12 d and verticaltransfer voltage P2 is supplied to transfer electrodes 12 c and 12 d.That is, with respect to semiconductor substrate 11, the set of transferelectrodes 12 a and 12 b apply a vertical transfer voltage of one phaseand the set of transfer electrodes 12 c and 12 d apply a verticaltransfer voltage of another phase.

As the materials of insulating layer 14, which insulates semiconductorsubstrate 11, transfer electrodes 12 a to 12 d, and supply wiring lines13 a and 13 b from each other, oxide films, etc., that transmit lightare used.

Supply wiring lines 13 a and 13 b are installed on the top surface ofcolumns H1 and Hm of photosensitive part 10 with their longitudinaldirection being set along the direction parallel to the respectivecolumns Hi of photosensitive part 10. Also, a protruding part 131 a isdisposed at the semiconductor substrate 11 side of the supply wiringline 13 a, and protruding part 131 a is electrically connected totransfer electrodes 12 a and 12 b. Likewise, a protruding part 131 b(not shown in FIG. 2B) is disposed at the semiconductor substrate 11side of the supply wiring line 13 b, and protruding part 131 b iselectrically connected to transfer electrodes 12 c and 12 d.

With the solid-state image pickup device of the present embodiment, whenan image of light is made incident from the top surface side ofphotosensitive part 10, the image of light is transmitted throughtransfer electrodes 12 a to 12 d and insulating layer 14 and reaches theinteriors of the respective pixels A of photosensitive part 10. Chargesare then generated in the interiors of the respective pixels A. Thesecharges are held once in the interiors of pixels A and then transferredin the vertical direction by vertical transfer voltages P1 and P2 beingapplied to the corresponding transfer electrodes 12 a to 12 d and bythese voltages being controlled by charge transfer control part 20. Thetransferred charges are then output to horizontal shift register 15. Thecharges are then transferred in the horizontal direction by horizontalshift register 15 and then input into and amplified by amplifying part16. The amplified charges are output to the exterior of the solid-stateimage pickup device as output signals according to the respective pixelsA.

By the above-described arrangement and operations, this embodiment'ssolid-state image pickup device provides the following effects. That is,supply wiring lines 13 a and 13 b, which are formed of a metal or metalsilicide that blocks light and were priorly installed at dead zones atthe respective ends of a CCD, are installed on top of pixels in thesolid-state image pickup device of this embodiment. Since dead zones forinstalling supply wiring lines 13 a and 13 b can thus be eliminated fromthe respective ends of a CCD, photosensitive part 10 can be made wide inCCD 1.

Also, supply wiring lines 13 a and 13 b are arranged to cover just apart of each of light-shielded pixels D. Here, light is made incident onthe other parts of light-shielded pixels D and output signals, which arelowered in output amounts to some degree, are output from thelight-shielded pixels D. Thus with the solid-state image pickup deviceof the above-described arrangement, the amount of lowering of theincident light amount on light-shielded pixels D can be corrected basedon the output signals that are lowered in output amounts.

FIG. 3A and FIG. 3B are tables showing (A) an example of output signaldata from pixels A and (B) an example of output signal data fromlight-shielded pixels D and pixels A in an FFT CCD with 1024 columns and64 rows. In regard to the method of correcting output signals, drivingan FFT CCD by TDI drive, which shall be described later, is equivalentto adding the signals of the 64 pixels in the vertical direction. Itthus becomes adequate to correct the output signals for the 1024channels in the horizontal direction that correspond to the respectivecolumns. Thus both the tables of FIG. 3A and FIG. 3B show variations ofthe output signals for the horizontal direction.

The pixel Nos. shown in FIG. 3A indicate the channel Nos. in thehorizontal direction. In regard to the output signals, an example of theoutput signals of channels 1 to 4 and 1021 to 1024 is shown. The outputsignals of channels 5 to 1020 are omitted since these are substantiallysimilar to those of channels 1 to 4 and channels 1021 to 1024.

As with FIG. 3A, the pixel Nos. shown in FIG. 3B indicate the channelNos. in the horizontal direction. Likewise, in regard to the outputsignals, an example of the output signals of channels 1 to 4 and 1021 to1024 is shown. However, the supply wiring lines are installed on top ofthe top surfaces of the pixels of columns H2 and H3 and columns H1022and H1023, and the pixels of all of the corresponding channels arelight-shielded pixels.

With pixels on which a supply wiring line is not installed, the mutualdifference of the output signals of adjacent pixels is minute, as shownin FIG. 3A. However as shown in FIG. 3B, in comparison to the outputsignals of pixels on top of which a supply wiring line is not installed,the output signals of light-shielded pixels are lowered in accordancewith the area covered by the supply wiring line, etc. By correcting forthis lowered amount of output signal, the influence of the supply wiringline on the output signal can be eliminated.

As methods of correcting output signals from light-shielded pixels, suchas shown in FIG. 3B, the following methods are effective.

That is, first, reference output signals, which are the output signalsobtained upon making a light of substantially uniform intensity incidenton the photosensitive part, are obtained. Then based on the referenceoutput signals of the light-shielded pixels, the output signals of thesame light-shielded pixels are corrected. Or, the output signals oflight-shielded pixels may be corrected based on the reference outputsignals of pixels adjacent the light-shielded pixels.

Or, correction based on the output signals of the pixels adjacent thelight-shielded pixels may be carried out without using reference outputsignals. That is, the output signals of the light-shielded pixels may becorrected using the correlation between the output signal values of thelight-shielded pixels and the output signal values of the adjacentpixels that are not light-shielded pixels.

As an example of a correction method, there is a method wherein, basedon reference output signals, a correction factor is computed such thatthe values obtained by multiplying the reference output signals of thelight-shielded pixels by the correction factor become substantiallyequal to the values of the reference output signals of the pixelsbesides the light-shielded pixels, and in picking up an image of light,the output signals of the light-shielded-pixels, among the outputsignals obtained by the image pickup, are corrected by multiplying bythe correction factor. By the above correction methods, the outputsignals of light-shielded pixels can be corrected readily.

For example, with a CCD, with which the pixel dimension is large suchthat one side of a pixel is approximately 48 μm, supply wiring lines ofapproximately 20 μm, which are smaller than the pixel dimension, areused. Though signals are lowered by amounts corresponding to the areasthat are hidden by the supply wiring lines, since lowering of suchdegree is reproducible, it can be corrected by an above-describedcorrection method.

With a CCD, with which the pixel dimension is small such that one sideof a pixel is approximately 24 μm, the proportion of the light-shieldedpart becomes large and the correction error becomes large. In such acase, binning, in which the charges generated in a predetermined number(for example, 2×2=4) pixels are added together to form an output signal,may be carried out and correction of the output signals of thelight-shielded pixels may be carried out thereafter.

Such binning is especially effective in cases where the presentsolid-state image pickup device is to be applied to a device with whicha problem will not arise even if the resolution is lowered. For example,for X-ray image pickup, the resolution may be lower in comparison tovisible light image pickup in many cases, and with panorama and cephalox-ray image pickup devices used for treatment in dentistry, theresolution may be approximately 5 to 10 Lp/mm. Or, with a panorama X-rayimage pickup device, a resolution of approximately 2 to 5 Lp/mm issufficient. Here, 2 to 5 Lp/mm is a resolution, with which 2 to 5 blackand white line pairs, drawn within a width of 1 mm, can be defined. Thiscorresponds to a pixel dimension of approximately 200 to 500 μm. In acase where the solid-state image pickup device is to be used as apanorama or cephalo X-ray image pickup device, even when binning, inwhich the output signals, for example, of 2×2=4 pixels are added, isperformed, such an X-ray image pickup device will function effectivelyas a sensor.

By performing binning as described above, a plurality of adjacent pixelscan be handled as a unit pixel. The effects that the supply wiring lineshave on the output signals of the unit pixels are thus lessened incomparison to those on the light-shielded pixels, and the output signalsof the light-shielded pixels can be corrected favorably. For example, inthe case where 2×2 binning is to be performed as described above and thesupply wiring lines are to be installed on the top surfaces of two ormore columns, the supply wiring lines should be installed so that thecolumns on which the supply wiring lines are installed will not beadjacent each other.

Also with the solid-state image pickup device illustrated in FIG. 1,FIG. 2A, and FIG. 2B, supply wiring lines 13 a and 13 b are installed onpixels of columns at the respective ends of photosensitive part 10. Bysuch installation, vertical transfer voltages P1 and P2 can be appliedefficiently onto transfer electrodes 12 a to 12 d from supply wiringlines 13 a and 13 b. Also, besides the present embodiment, by installingsupply wiring lines 13 a and 13 b at columns substantially at the centerof photosensitive part 10, the same effects as those of the presentembodiment can be obtained. Furthermore, since the number of supplywiring lines will be the minimum necessary by the above configurations,the number of light-shielded pixels can be made low.

Supply wiring lines 13 a and 13 b are installed as a set of two wiringlines for applying the two-phase vertical transfer voltages P1 and P2and the two supply wiring lines that form a set are installed above asingle column of pixels. By installing the supply wiring lines in thismanner, the number of light-shielded pixels D, which are required perset of supply wiring lines and with which the output signals arecorrected, can be made low.

The TDI (Time Delay Integration) drive method can be cited as method ofperforming image pickup of image pickup subjects that move at a fixedvelocity, such as objects on a belt conveyor, etc. In the TDI drivemethod, while performing charge transfer between potential wells at arate that is in accordance with the movement velocity of the imagepickup subjects, further accumulation of charges is performed to therebyperform image pickup of moving images of light without blur. Such adrive method is realized by the control of vertical transfer voltages P1and P2 by the above-mentioned charge transfer control part 20. By chargetransfer control part 20 of the solid-state image pickup deviceperforming such charge transfer by the TDI drive method, image pickupobjects moving at a fixed velocity can be picked up clearly. This TDIdrive method is also used often in the above-mentioned panorama andcephalo X-ray image pickup devices as well.

The effect of eliminating dead zones by the above-described arrangementbecomes especially effective in a solid-state image pickup device array,wherein a plurality of the solid-state image pickup devices are alignedin a manner such that photosensitive parts 10 are aligned adjacent eachother in the horizontal direction.

FIG. 4 is a schematic arrangement diagram of a solid-state image pickupdevice array using this invention's solid-state image pickup devices asviewed from the top surface side. With the solid-state image pickupdevice array shown in FIG. 4, a plurality of CCDs 1, shown in FIG. 1,are aligned so as to be adjacent each other in the horizontal direction.

With a solid-state image pickup device array, an image pickup subject oflarge dimensions, which cannot be picked up with a single solid-stateimage pickup device, is picked up by a plurality of solid-state imagepickup devices. With the prior-art solid-state image pickup devicearray, the respective end parts of each photosensitive part at which thesupply wiring lines are installed are not used as photosensitive partsand pixels are not disposed thereat. Thus with an image that is pickedup across a plurality of the photosensitive parts, a fixed amount ofnon-image-pickup parts arise in the interior of the image due to deadzones for supply wiring line installation that exist between therespective photosensitive parts.

With the solid-state image pickup device array shown in FIG. 4, sincedead zones for the installation of supply wiring lines are eliminated bythe installation of supply wiring lines 13 a and 13 b on top of pixelsin the solid-state image pickup devices, the non-image-pickup parts thatexist in an image picked up by the solid-state image pickup device arraycan be made small.

Here, an example of an X-ray image pickup device used for treatment indentistry shall be described. With a cephalo X-ray image pickup deviceused for treatment in dentistry, a length of approximately 220 mm isrequired as the length of an effective photosensitive region, which is aregion in the solid-state image pickup device wherein image pickup isenabled, and with a panorama X-ray image pickup device, a length ofapproximately 150 mm is required for the effective photosensitiveregion. However, it is difficult to realize an effective photosensitiveregion of such length with a single solid-state image pickup device. Aplurality of solid-state image pickup devices are thus aligned and seton a ceramic or printed circuit board to obtain the length required ofthe effective photosensitive region.

With the prior-art solid-state image pickup device, if the width of thedead zone at one end part of a photosensitive part is, for example, 100μm and the width of the dead zone at the other end is 200 μm, a deadzone of 300 μm in total is formed at each seam between photosensitiveparts. Due to these dead zones, non-image-pickup parts exist in apicked-up image and this can influence diagnosis in dentistry. Theexistence of non-image-pickup parts in a picked-up image is thus aproblem with prior-art solid-state image pickup device arrays. However,by using the solid-state image pickup device array shown in FIG. 4, deadzones due to the installation of supply wiring lines are eliminated andthe non-image-pickup parts can be made small.

FIG. 5A and FIG. 5B are (A) a top view and (B) a section along arrowsII-II showing a part of the arrangement of a CCD 2 of a solid-stateimage pickup device of a second embodiment. CCD 2, shown in FIG. 5A andFIG. 5B, comprises a semiconductor substrate 11, transfer electrodes 12a to 12 d, supply wiring lines 23 a and 23 b, and an insulating layer14. Of these, since the arrangements of parts besides supply wiringlines 23 a and 23 b are the same as those of the solid-state imagepickup device of the first embodiment, description thereof shall beomitted.

Supply wiring lines 23 a and 23 b are installed on the top surfaces ofcolumns H1, Hm, and a substantially central column with theirlongitudinal direction being set along the direction parallel to therespective columns Hi of photosensitive part 10. Also, a protruding part231 a is disposed on the supply wiring line 23 a and a protruding part231 b is disposed on the supply wiring line 23 b, and via theseprotruding parts, vertical transfer voltage P1 is applied to transferelectrodes 12 a and 12 b and vertical transfer voltage P2 is applied totransfer electrodes 12 c and 12 d.

With the solid-state image pickup device of the present embodiment,since the dead zones for installing supply wiring lines 23 a and 0.23 bcan be eliminated from the respective ends of a CCD, photosensitive part10 in CCD 2 can be made wide. Also, supply wiring lines 23 a and 23 bare arranged to cover only a part of each light-shielded pixel D. Theamount of lowering of the incident light amount on light-shielded pixelsD can thus be corrected based on the output signals that are lowered inoutput amounts.

Also, in addition to the positions in the first embodiment, a set ofsupply wiring lines 23 a and 23 b are installed on the top surface ofthe substantially central column of photosensitive part 10. Thedistances between supply wiring lines 23 a mutually and the distancesbetween supply wiring lines 23 b mutually are thus shortened. Since theinfluence due to the electrical resistances of transfer electrodes 12 ato 12 d can thus be restrained at a low level, the charge transfer rateof CCD 2 can be made high and CCD 2 can be driven at high speed.

Supply wiring lines 23 a and 23 b may be installed just on the topsurface of the substantially central column of photosensitive part 10.By such installation, vertical transfer voltages P1 and P2 can beapplied efficiently onto transfer electrodes 12 a to 12 d from supplywiring lines 23 a and 23 b. Also, since the number of supply wiringlines becomes the minimum necessary, the number of light-shielded pixelscan be made low.

FIG. 6A and FIG. 6B are (A) a top view and (B) a section along arrowsIII-III showing a part of the arrangement of a CCD 3 of a solid-stateimage pickup device of a third embodiment. CCD 3, shown in FIG. 6A andFIG. 6B, comprises a semiconductor substrate 11, transfer electrodes 12a to 12 d, supply wiring lines 33 a and 33 b, and an insulating layer14. Of these, since the arrangements of parts besides supply wiringlines 33 a and 33 b are the same as those of the solid-state imagepickup device of the first embodiment, description thereof shall beomitted.

Supply wiring lines 33 a and 33 b are installed on the top surfaces ofarbitrary columns Hi on the top surface of insulating layer 14, withtheir longitudinal direction being set along the direction parallel tothe respective columns Hi of photosensitive part 10. Here, supply wiringlines 33 a and 33 b are installed on mutually different columns. Also, aprotruding part 331 a is disposed on the supply wiring line 33 a and aprotruding part 331 b is disposed on the supply wiring line 33 b, andvia these protruding parts, vertical transfer voltage P1 is applied totransfer electrodes 12 a and 12 b and vertical transfer voltage P2 isapplied to transfer electrodes 12 c and 12 d.

With the solid-state image pickup device of the present embodiment,since the dead zones for installing supply wiring lines 33 a and 33 bcan be eliminated from the respective ends of a CCD, photosensitive part10 in CCD 3 can be made wide. Also, supply wiring lines 33 a and 33 bare arranged to cover only a part of each light-shielded pixel D. Theamount of lowering of the incident light amount on light-shielded pixelsD can thus be corrected based on the output signals that are lowered inoutput amounts.

Also, with supply wiring lines 33 a and 33 b, the two supply wiringlines that form a set for applying the two-phase vertical transfervoltages P1 and P2 are installed on top of pixels of mutually differentcolumns. By the supply wiring lines being installed in this manner, thearea covered by supply wiring lines of each light-shielded pixel islessened and the lowering of the incident light amount onto thelight-shielded pixels is thus made small. The correction of the outputsignals of the light-shielded pixels can thereby be facilitated.

This invention's solid-state image pickup device is not restricted tothe above-described embodiments and various modifications are possible.For example, with regard to the supply wiring lines, an arbitrary numberthereof may be installed on the top surfaces of pixels at arbitrarylocations besides those of the above-described embodiments and may thusbe designed as suitable according to the required charge transfer rate,correction method, etc.

Also, with each of the above-described embodiments, a two-phase driveCCD is used. Besides this, even when a CCD of three-phase drive orhigher is used, a solid-state image pickup device by this invention canbe arranged favorably by installing the required number of supply wiringlines on top of pixels.

Also, though with each of the above-described embodiments, an FFT CCD isused as the CCD, another type of CCD may be used instead. For example,by equipping the supply wiring lines of the above-described arrangementin a frame transfer type CCD (FT CCD), having a charge accumulating partbetween a photosensitive part and a horizontal shift register, thephotosensitive part of the solid-state image pickup element can be madewide.

Industrial Applicability

This invention's solid-state image pickup device and solid-state imagepickup device array can be used as a solid-state image pickup device andsolid-state image pickup device array, with which the dead zones can bemade small and the photosensitive parts can be made wide. That is, withthe solid-state image pickup device, since by the installing of supplywiring lines, which are formed of light-blocking material, on top ofpixels, the dead zones for installing supply wiring lines, which existedat the respective end parts in the horizontal direction of thephotosensitive part in the prior art, can be eliminated, thephotosensitive part can be made wide. Also by eliminating the dead zonesof the solid-state image pickup device, parts at which image pickup isnot performed can be lessened in cases where a plurality of thesolid-state image pickup devices are used adjacent each other in thehorizontal direction. Also, the supply wiring lines are arranged tocover only a part of the light-shielded pixels. Since light is madeincident on the other parts of the light-shielded pixels, outputsignals, which are lowered to some degree in output amount, are outputfrom the light-shielded pixels. Thus with the solid-state image pickupdevice of the above arrangement, the lowering of the incident lightamount on the light-shielded pixels can be corrected based on the outputsignal.

Also, with the solid-state image pickup device array, since theintervals between the respective photosensitive parts can be made narrowby the use of the above-described solid-state image pickup devices,non-image-pickup parts that exist in an image that has been picked up bythe solid-state image pickup device array can be made small.

1. A solid-state image pickup device comprising: a photosensitive part,having m×n pixels, formed on a semiconductor substrate, which includes ap-type semiconductor layer and an n-type semiconductor layer, andaligned two-dimensionally along m columns (where m is an integer of 2 ormore), which partition a horizontal direction, and n rows (where n is aninteger of 2 or more), which partition a vertical direction, and pickingup an image of light that is made incident thereon; a transferelectrode, being installed on top of said pixels with the longitudinaldirection thereof being set along the horizontal direction of saidphotosensitive part and being applied a vertical transfer voltage thattransfers charges generated in said pixels in the vertical direction;and a supply wiring line, formed of metal or metal silicide, installedso as to cover a part of a light-shielded pixel, which is apredetermined pixel among said pixels, and with the longitudinaldirection thereof being set along the vertical direction of saidphotosensitive part, being electrically connected to said transferelectrode, and applying said vertical transfer voltage to said transferelectrode; wherein being arranged to enable correction of the amount oflowering of an output signal, output by said light-shielded pixel, dueto said supply wiring line.
 2. The solid-state image pickup deviceaccording to claim 1, wherein said supply wiring lines are installed ontop of said pixels of columns, among said m columns, at the respectiveends of said photosensitive part.
 3. The solid-state image pickup deviceaccording to claim 1, wherein said supply wiring line is installed ontop of said pixels of a substantially central column, among said mcolumns of said photosensitive part.
 4. The solid-state image pickupdevice according to claim 1, wherein said supply wiring line isinstalled as a set of k supply wiring lines (where k is an integer of 2or more) for applying said vertical transfer voltages of k phases andthe k said supply wiring lines that form a set are installed on top ofsaid pixels of one column.
 5. The solid-state image pickup deviceaccording to any of claim 1, wherein said supply wiring line isinstalled as a set of k supply wiring lines (where k is an integer of 2or more) for applying said vertical transfer voltages of k phases andthe k said supply wiring lines that form a set are installed in adispersed manner along a plurality of columns.
 6. The solid-state imagepickup device according to claim 1, wherein light of substantiallyuniform intensity is made incident in advance on said photosensitivepart to determine a reference output signal and the output signal ofsaid light-shielded pixel is corrected based on said reference outputsignal.
 7. The solid-state image pickup device according to claim 1,wherein the output signal of said light-shielded pixel is correctedbased on the output signal of the non-light-shielded pixel adjacent saidlight-shielded pixel.
 8. The solid-state image pickup device accordingto claim 1, wherein binning, in which the charges generated in apredetermined number of said pixels are added to form an output signal,is performed.
 9. The solid-state image pickup device according to claim1, wherein said vertical transfer voltage is controlled by the TDI drivemethod, in which charges are transferred in the vertical direction at arate corresponding to the movement velocity of an image pickup subjectto perform image pickup without blur of said image of light of saidimage pickup subject.
 10. A solid-state image pickup device arraywherein a plurality of the solid-state image pickup devices according toclaim 1 are aligned in a mutually adjacent manner with saidphotosensitive parts being aligned in the horizontal direction.